---
title: "gen_estimateGas"
description: "Reserved for estimating gas for a GenLayer transaction. Not implemented — the method is registered and reachable, but every call returns an error."
source: https://docs.genlayer.com/api-references/genlayer-node/gen/gen_estimateGas
last_updated: 2026-10-19
---

# gen_estimateGas

### gen_estimateGas

Reserved for estimating gas for a GenLayer transaction. **Not implemented** — the method is registered and reachable, but every call returns an error.

**Method:** `gen_estimateGas`

**Parameters:** None currently read — any params supplied are ignored because the method returns before parsing them

**Returns:** Nothing. The call always fails with JSON-RPC error code `-32004`

**Example Request:**

```json
{
  "jsonrpc": "2.0",
  "method": "gen_estimateGas",
  "params": [],
  "id": 1
}
```

**Example Response:**

```json
{
  "jsonrpc": "2.0",
  "error": {
    "code": -32004,
    "message": "method not implemented: gen_estimateGas"
  },
  "id": 1
}
```

**Notes:**

- The method is registered in the `genlayer` endpoint group, so it is reachable and rate-limited like any other method — it just cannot succeed
- The error code is `-32004` ("method not supported"), not `-32601` ("method not found"): the node recognises the method and is declining to serve it, rather than failing to route it
- Disabling the `genlayer` group, or this method specifically via `endpoints.methods`, changes the response to the same `-32004` code with a "method not supported" message
- Do not use gas estimation to size a transaction budget today; set fees explicitly instead

**cURL Example:**

```bash
curl -X POST http://localhost:9151 \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "gen_estimateGas",
    "params": [],
    "id": 1
  }'
```